Pike (Esox lucius) and Perch (Perca fluviatilis)

Life Histories

PIKE

Pike are present throughout the Ness system, with the majority of lochs holding fairly substantial populations. Its good camouflage and size contribute to its success. They grow large where there is a plentiful food supply, a fish of 72lb was caught in Loch Ken, Kirkcudbright in the 18^th century, with fish of 30lb not uncommon. Pike will eat most species of fish including each other, some are specialised feeders, for example some larger fish will feed mainly on smaller pike, some will feed only on fry or minnows. They do however, have a notorious reputation, often unfairly. They are seen as beneficial n some fisheries acting as a scavenger and preying on stunted or injured fish, this is particularly true of larger specimens.

 Between February and May females gather in the shallow weedy areas often followed by numerous smaller males. Eggs are laid in weed filled shallows and flooded water meadows. Smaller fish usually lay eggs first, between 10,000 and 20,000 eggs are produced per pound of female weight. Egg clusters stick to plant stems and stones. After 10-15 days larvae (9mm) long hatch but remain attached by their heads to stems and stones. Mouths are not yet formed and they obtain food via the yolk sac.

When the yolk sac is finished, the larvae, with dark eye stripes are free swimming and feed on small water fleas and other invertebrates. Cannibalism and competition for food take their toll of young fish, but once reaching a weight of several pounds it has few enemies except man, bigger pike and otters.

PERCH

Perch are found in a number of locations within the Ness catchment with reports have perch being captured in the Caledonian Canal also. They are easy to distinguish with a double dorsal fin, one of which is spiny. They have distinctive black bands on a greenish background, the lower fins are often tinged with red. They have a relatively small head, large moth and a spine on the gill cover. They can reach a length of 50cm but are often much smaller.

 Perch were one of the most common fish found in Britain but in the 1970’s they were hit by a virus that killed most of them. This disease seems to have run its course and more fish are present. A peculiar feature of these larger perch is that they produce large numbers of stunted, smaller fish.

Perch lay their eggs in strings attached to water plants in slow moving or still water, this usually occurs in early spring. It is often thought that they can be spread by birds where the weed containing eggs has wrapped around their feet. When perch are young, they swim in large shoals, camouflaged among water plants. Slender males (50-75mm) may become sexually mature, they are probably only 6-12 months old, Females grow much larger and become mature at around three yeas of age. Perch are carnivorous, feeding on small fish and crustaceans.